1. Field of the Invention The present invention relates to a method for producing refreshable frozen foods. The method is suitable for freezing foods in a liquid anti-freezing medium so as to have refreshable foods which can be restored to an original fresh raw state by defrosting. A super rapid freezer is used in the method.
2. Related Art Statement
Cold air has hitherto been used as a cold medium for freezing and preserving foods such as edible meats, fish and vegetables and the like, and a freezing system with the cold air or nitrogen gas has been used.
The prior method for freezing edible meat and the freezer thereof, as shown in FIG. 11, uses a freezing system with cold air by housing a food F within a sealed freezing chamber 1. Cold air N is sprayed at the food F in the direction of the arrows.
According to this system, when edible meat is frozen, there are such disadvantages that the condition of frozen meat is worse, drippings are produced when defrosting, and components of meat flow out together with blood, thereby lowering the taste of edible meat. Moreover, food is frozen by a cold air flow at super low temperature, such as -20.degree. C. to -40.degree. C., so, that uneven freezing is produced at a deep side, a side surface, a bottom portion and the like of a food where a cold air flow cannot directly be made to contact with the food.
Freezing quality of a food depends upon how quick the food is passed through the maximum freezing forming zone (i.e. -1.degree. C. to -10.degree. C.) of a food to be frozen.
A frozen crystal of water in frozen meat largely breaks cells at slow freezing. As a result, dripping is liable to be caused and the components of meat which keeps freshness and flavor are lost at the time of defrosting. Also, the degree of freshness and the flavors are deteriorated, and decomposition is accelerated by adherence of various germs to the meat.
Japanese Laid-open Patent Application No. 3,736/87 discloses a process for quickly freezing sea food. A device for carrying out this process comprises an agitating shaft, freezing piping and a basket for housing meat or sea food within a tank. A motor and a compressor are provided outside the tank. The process includes the steps of cooling brine, adding oil to a solution consisting of propylene glycol, potassium chloride and water, and immersing and freezing sea food in the brine. Such a freezing process is known.